Graph Fused Lasso + H3

gfl_with_h3.py

from h3 import h3
from pygfl.easy import solve_gfl

def build_neighbor_edges(hexids):
    # Hash the hexid to the position so we can easily look
    # up where the original hexid position is in the array.
    hexid_to_position = {h:ii for ii,h in enumerate(hexids)}
    edges = []
    for h in hexids:
        for n in h3.k_ring(h,1):
            if n != h and n in hexid_to_position:
                edges.append((hexid_to_position[h], hexid_to_position[n]))
    return np.array(edges)

def gfl_solve_h3(hexids, values):
    # Edges has the positions of "from" and "to" hexids in the hexids array.
    edges = build_neighbor_edges(hexids)
    # gfl_solution is the fitted values, same dimension as values array.
    gfl_solution = solve_gfl(values, edges)
    return gfl_solution